This application claims the priority of German application 197 26 536.7, filed in Germany on Jun. 23, 1997, and International PCT Application PCT/EP98/03611 filed in the European Patent Office on Jun. 16, 1998, the disclosures of which are expressly incorporated by reference herein.
The invention relates to a hinge for the pivotable mounting of a structural part on which there acts an adjusting force which causes said structural part to pivot, and having a pivot brake which inhibits said pivoting and is in the form of interacting cylinder wedge surfaces on the hinge pin and on at least one of the hinge plates.
Within the context of the application, hinge is intended to mean an articulated connection with at least one axis which has a shaft in the form of a hinge pin and a hub in the form of a pivotable hinge plate. Such an articulated connection may also be expressed, for example, as a door hinge or piano hinge. The hinge may also have two parallel axes between which a hinge bridge is arranged. The hinge serves for the pivotable mounting of a structural part. This means that the mounting element of the hinge is arranged in a usually fixed manner. However, this does not prevent said mounting element, on its part, from being mounted pivotably in a further articulated connection, for example the abovementioned hinge bridge about the abovementioned second axis.
Pivot brake is intended to mean an inhibiting device which sets a certain resistance, in other words an opposing force against the pivoting of the pivotable mounted structural part under the action of an adjusting force, which opposing force is usually smaller than the adjusting force. As long as the adjusting force remains smaller than the opposing force, the inhibiting device acts as a pivot stop and prevents the structural part from pivoting under the action of the adjusting force.
The adjusting force acting on the pivotably mounted structural part may be of any desired nature. It may be formed by the gravitational force, for example, on structural parts that can be pivoted about a horizontal axis, such as swing-action covers or swing-action seats; it may be applied by an energy store, such as a spring, or it may be exerted spontaneously, for example by a gust of wind acting on a door.
Cylinder wedge surfaces are intended to mean cams which, on mutually facing surfaces of the hinge pin and of the hinge plate which are equiaxial with the axis of the hinge, slope gradually upwards in wedge form from an imaginary cylinder surface in each case and then drop down sharply again onto the cylinder surface, it being the case that the cams are arranged on an inner surface of one of the structural parts and on an outer surface of the other structural part and the directions of upward slope of the cams oppose one another, and it being the case that provided between the cylinder wedge surfaces in a joining position is a joining gap which is smaller than the height of the cams beyond their respective reference cylinder surface.
DE 44 06 824 C describes a hinge with pivot stop which prevents a part which is mounted in a hinge bolt from being pivoted under the action of adjusting forces, which are not intended to cause pivoting. This achieves the situation where, for example, a door has a self-securing action in all pivot positions of its open-angle range. In this case, the braking force of the pivot brake thus always exceeds the adjusting force, which is not intended to cause pivoting.
However, there are a number of known application cases in which structural parts are intended to be pivotable with respect to one another by virtue of adjusting forces acting on them, although the intention is for this pivoting ability to be inhibited, braked or damped to a more or less pronounced extent and/or merely over part of the pivoting range. In many cases, furthermore, it is advantageous if the braking action may be calculated so as to prevent pivoting by adjusting forces which are below a threshold value. Examples of this are engine bonnets or boot lids, which have to be capable of being opened or closed by hand, but which are not intended to bang shut from the open position under the action of gravitational force and are not intended to bang shut without braking once they have been lowered from the open position. Another example is constituted by vehicle doors which, depending on their position and depending on the inclination of the vehicle, are subjected, by the gravitational force or a gust of wind, to very different moments, which are intended to be compensated for at least to the extent where a door is retained in the open position and/or does not unintentionally pivot out of this position with accelerating action without braking.
A further example is constituted by swing-action seats in public transport or in fixed seating arrangements, said swing-action seats usually being guided into the swung-up position by spring force. It is frequently desirable for said seats to be retained in a swung-down position, in order that they do not swing upwards when one stands up for a brief period of time. The intention is for the automatic swing-up operation to be initiated by a brief lifting action. Furthermore, it is not intended for such seats to be accelerated to a pronounced extent under the action of the spring force, in order that they do not strike against their top abutment. Their swing-up operation is thus intended to take place with braked action at least in the end region of their pivoting movement.
Accordingly, the object of the invention was to specify, for a hinge having a pivot brake with cylinder wedge surfaces, a rule for calculating the braking action and embodiments which can best fulfil these requirements. The invention achieves this object in that the progression of the braking moment of the pivot brake is adapted to the progression of adjusting forces acting on the structural part over the pivot angle to the effect that the adjusting force is opposed by braking force which is smaller than the adjusting force at least over a considerable part of the pivot angle.
This achieves the situation where it is only the difference between the adjusting force and the braking force which acts on the structural part. The structural part can thus be pivoted by the adjusting force over a considerable part of its pivot angle, but only in a braked, inhibited and slowed-down manner. It is thus not a more or less arbitrary progression of the braking moment of the pivot brake between assumed start and end values which is selected, but rather a progression which is adapted to the progression of the adjusting forces acting on the pivotable structural part and is determined by parameters such as mass of the pivotable structural part, swivel arm of the center of gravity of the structural part, pivot angle, inclination of the pivot axis in space and the like. Since these parameters may differ greatly from case to case, the progression of the adjusting forces and the sought-after progression of the pivoting movement have to be determined before the progression of the braking moment is established.
In one or more narrow regions of the pivot angle of the structural part it is contemplated, for the braking force of the pivot brake to exceed the adjusting force, with the result that, rather than being pivoted by the adjusting force in these regions, the structural part is blocked. These regions are usually the start or end regions of the pivot angle or, in general terms, positions in which the structural part is to be retained automatically.
In many cases, it is also advantageous if, according to contemplated arrangement, the pivot brake does not set any braking force against the adjusting force in a region of the pivot angle. This relates, in particular, to a region upstream of the start or end point of a pivot angle, which is intended to be reliably reached and retained by means of the adjusting force.
This can be achieved by corresponding dimensioning, or by appropriate angle positioning, of the wedge surfaces. For this purpose, according to contemplated arrangements, the pivot brake may be provided with a plurality of wedge surfaces which take effect in the different regions of the pivot angle and, depending on the sought-after functioning, may be provided with the same direction of slope or with opposite directions of slope. In the former case, the wedge-surface pairings take effect one after the other and the pivot brake exerts a braking force over a large pivot range. In the second case, the wedge-surface pairings come into effect depending on the pivoting direction, as a result of which the pivot brake exerts increasing braking force in the two pivoting directions. The wedge surfaces may be provided with the same or different slopes, with the result that, depending on the pivoting direction, the pivot brake may be imparted different braking action or braking action which increases progressively or degressively with the pivot angle.
It has been found to be sufficient in most cases if the pivot brake uses up at least 20% of the adjusting work performed by the adjusting force, that is to say of the product of adjusting force and pivoting distance, by braking work, that is to say by the product of braking force and pivoting distance, i.e. if the pivot brake converts this into heat energy in order to achieve sufficient braking of the movement of the respectively pivot-braked structural part.
Precisely angled adjustment of the wedge surfaces is virtually always necessary in order to allow the braking action of the pivot brake to set in, and increase, at the correct pivot angle. This is made possible by the arrangements (i) wherein the hinge pin has means for adjusting its angle position, and/or (ii) wherein the hinge pin in a second axial region, and the hinge-pin-securing hinge plate have conical fitting surfaces which can be pressed one inside the other, and/or (iii) wherein the hinge pin, in a second axial region and the hinge-pin-securing hinge plate have fitting surfaces with interengaging toothing arrangements.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.